Simple string manipulation

Although an experienced programmer I’m completely new to Ui.Vision so please forgive me if I have missed something obvious.
I’m trying to update some files on a web site.
Following tutorials I can log in, delete existing files and upload new ones BUT I need to know when they are all uploaded. Luckily the website displays the total files and I can access this using:
However number typically returns
and I need to extract the 9 or whatever figure it is to compare with the final expected total.
Is there an instr type function or even a left/mid/right string manipulation function?
I suppose I could create a string with the desired number in it and compare but I feel I’m missing the very simplest functions of a language.
Thanks in

Here is a list of code snippets for string manipulation